#include<stdio.h>

int nums[10];
int month = 10;
int year; // default value is 0

void increase();


int main() {

    increase();
    // int month = 12; // local variable
    // extern int month; // file scope variable
    printf("month = %d\n", month);
    printf("year = %d\n", year);

    return 0;
}

void increase() {
    month++; // 11
    year++; // 1
}